1. Field of the Invention
This invention relates generally to a two component effervescent dentifrice wherein, upon mixing of the separate components during brushing, significantly enhanced consumer perceived sensory sensations are provided which instill the consumer a perception of enhanced cleaning performance, and more particularly to a two component peroxide containing oral composition that provides enhanced sensory cues as well as providing a tooth whitening benefit.
2. The Prior Art
A tooth is comprised of an inner dentin layer and an outer hard enamel layer that is the protective layer of the tooth. The enamel layer of a tooth is naturally an opaque white or slightly off-white color. It is this enamel layer that can become stained or discolored. The enamel layer of a tooth is composed of hydroxyapatite mineral crystals that create a somewhat porous surface. It is believed that this porous nature of the enamel layer is what allows staining agents and discoloring substances to permeate the enamel and discolor the tooth.
Many substances that a person confronts or comes in contact with on a daily basis can "stain" or reduce the "whiteness" of one's teeth. In particular, the foods, tobacco products and fluids such as tea and coffee that one consumes tend to stain one's teeth. These products or substances tend to accumulate in the protein pellicle enamel layer of the tooth. These staining and discoloring substances can then permeate the enamel layer. This problem occurs gradually over many years, but imparts a noticeable discoloration of the enamel of one's teeth.
There are available in the marketplace oral compositions for home use which contain 1-3% by weight concentrations of a peroxide compounds such as hydrogen peroxide and when applied on the teeth effect whitening.
Illustrative of oral compositions containing peroxygen compounds for whitening teeth include U.S. Pat. Nos. 5,766,574 and 5,648,064.
U.S. Pat. No. 5,766,574 discloses dual component whitening dentifrice which comprises a first dentifrice component containing a peroxide compound such as urea peroxide and a second dentifrice component containing an abrasive such as alumina or silica which is incompatible with the peroxide, the first and second dentifrice components being maintained separate from the other until dispensed and combined for application to teeth requiring whitening.
U.S. Pat. No. 5,648,064 discloses a two component whitening dentifrice composition which discloses a first component containing a peroxygen compound such as hydrogen peroxide and a second dentifrice component containing a manganese coordination complex compound such as manganese gluconate, which activates the peroxygen compound and accelerates the release of active oxygen for rapid whitening action, the first and second components being maintained separate from the other until dispensed for application to teeth.
Further, it is known that bicarbonate-acid mixtures in toothpaste compositions will create an effervescent effect and that such effervescent effect can provide certain sensory and tooth cleaning benefits. For example, U.S. Pat. No. 5,885,871 discloses a two component effervescent dentifrice composition wherein the effervescent signal produced by the dentifrice derives form the evolution of carbon dioxide upon the mixing of a high alkaline pH paste (pH range 8-9) and a low acid pH (pH 2-4) gel.
There is an ongoing need for new and novel sensory benefits to promote the use of dentifrices and particularly in dentifrices used in the tooth whitening.